Earlier work on the supersymmetric extensions of the BMS\(_4\)  algebra considered fermionic extensions with only a finite number of fermionic generators - the standard supercharges - both at null infinity [1]} and spatial infinity [2]}. Extensions involving an infinite number of fermionic generators have been studied recently at null infinity [3]}, [4]}, [5]}, mostly in the context of “celestial CFT”. Our work differs from those interesting investigations in that we deal with spatial infinity and insist throughout in having a well-defined moment map. We denote by SBMS\(_4\)  the supersymmetric extension of the BMS\(_4\)  algebra with an infinite number of fermionic generators that emerges in our work.
